An arrangement of ferromagnetic materials, like iron or steel cores, designed to guide and concentrate magnetic flux. It operates on principles similar to an electrical circuit, where magnetomotive force drives flux through a path of a certain reluctance. Engineers design these paths in transformers, motors, and relays to maximize efficiency and minimize stray magnetic fields by keeping the flux tightly contained within the core.
The air gap in the contactor increases the reluctance of the magnetic circuit, which requires a higher pull-in current.
Related terms
Core loss
The electrical energy dissipated as heat within the magnetic core of an AC device.
Transformer
A static electromagnetic device that transfers electrical energy between circuits at changed voltage levels.
Field coil
An electromagnet winding used to generate a steady magnetic field in a rotating machine.